By the year 2025 it is estimated that two thirds of the world population will have limited if any access to fresh water. This scenario is further complicated due to population growth, industrialization, pollution of ground water and climate change.
In addition, the world's population has already exceeded seven billion people and it continues to grow exponentially higher. By the year 2050 we may reach 9.5 billion people. While the planet's population is increasing, we also continue the pollution of lands, rivers, and oceans through toxic emissions, mainly by burning fossil fuels to power heavy industry and vehicles. These are the facts of our daily news and contribute to global warming and climate change.
Perhaps more important to the planet's inhabitants than temperature will be how much rising greenhouse gases crank up the water cycle. It is predicted that precipitation will increase where it is already relatively high—tropical rain forests, for example—and decrease it where it is already low, as in the subtropics. The oceans cover 71% of the globe, hold 97% of its water, and receive 80% of its precipitation. Dry places getting drier would mean longer and more intense droughts, and a stronger need for fresh water in those locations. There is mounting scientific evidence which shows that only a small change in global warming can drastically affect the living conditions of billions of people globally, particularly due to the effect on potential water shortages and all that relies on water, from food to sanitation and public health.
Desalination plants are currently used to create fresh water from salt water, which is commonly sourced from the ocean. A common method used in the desalination process is to filter the water and then use reverse osmosis (RO) to remove the remaining dissolved solids and salts to produce fresh water. However, there are several concerns with desalination because of the potential negative environmental impacts. Electric energy, the main power source for RO desalination plants, results in the emission of air pollutants and greenhouse gases that further exacerbate climate change. Current state-of-the-art RO plants consume between 3 and 4 kWh/m3 of produced water and emit between 1.4 and 1.8 kg CO2/m3 of produced water. However, this energy requirement does not include the energy needed for intake, discharge, pre-treatment, post-treatment and brine for which additional 1 kWh/m3 is needed.
Large RO plants may require an additional and separate power plant just to supply the huge amount of electrical power needed for its function. The additional power plant creates a lot of CO2 emissions and other pollution, a real negative impact on the environment. Also, before the sea water is pumped through the RO filters at high pressure, it must first be pumped through special filters to eliminate algae and particulates, adding to the energy consumption and costs of the process. Additionally, RO plants cause a hazard to the sea/ocean environment, because the high-speed pumping into the filters can capture and kill many small living organisms, like passing fish.
A solution is needed which can increase self-sufficiency. In particular, the costs of producing clean water heavily tax the environment; there is a need for a low-cost method for meeting those needs on a mass scale.